A new study by Cornell University researchers reveals that cumulative social advantages across a lifetime—from parental warmth in childhood to community engagement and friendships in adulthood—may slow down the biological processes of aging. This effect is reflected in a younger biological age when measured through DNA methylation patterns, also known as “epigenetic clocks.”
Published in the October issue of Brain, Behavior and Immunity – Health, the research analysed data from over 2,100 adults enrolled in the long-running Midlife in the United States (MIDUS) study. It found that individuals with higher levels of what researchers term “cumulative social advantage” exhibited slower epigenetic aging alongside lower levels of chronic inflammation.
Professor Anthony Ong of Cornell University, lead author of the study, explained that the research focused on epigenetic clocks—molecular signatures that estimate the pace of biological aging. Two specific clocks, GrimAge and DunedinPACE, known for predicting morbidity and mortality, showed younger biological profiles in adults with stronger, sustained social networks.
“Cumulative social advantage encompasses the depth and breadth of one’s social connections throughout life,” Professor Ong said. “We considered four key domains: parental warmth and support in childhood, connection to one’s community and neighbourhood, involvement in religious or faith-based groups, and ongoing emotional support from friends and family.”
The researchers posited that sustained social advantages influence the biological systems associated with aging, including epigenetic regulation, inflammation, and neuroendocrine pathways. Remarkably, higher social advantage correlated with reduced levels of interleukin-6, a pro-inflammatory molecule associated with heart disease, diabetes, and neurodegenerative disorders.
However, no significant links were observed with short-term stress markers such as cortisol.
Unlike previous studies that examined singular social factors in isolation—such as marital status or number of friends—this research combined early and later-life relational resources into a multidimensional measure, capturing how social advantages accumulate and cluster over time.
“What stands out is the cumulative effect of these social resources,” Professor Ong emphasised. “It is not merely about having friends today but about how social connections have deepened and grown throughout your lifetime. This gradual accumulation profoundly shapes health outcomes.”
The study cautions that isolated social interactions, for instance a single friendship or brief volunteer experience, cannot by themselves reverse biological aging. Rather, the consistency and depth of social ties built across decades and different life spheres are crucial.
“Think of social connections like a retirement fund,” Professor Ong said. “The earlier and more consistently you invest, the greater the returns. Our findings show those returns are biological as well as emotional. People with richer social connections literally age more slowly at the cellular level. Healthy aging means maintaining both physical health and strong social bonds—they are inseparable.”
